Collagenase or relaxin in transdermal application is worthless. They are peptide hormones and cannot be carried through the skin.
Collagenase are enzymes and are the only direct mean for the body to break down the collagen peptide bonds within connective tissue, thus extremely effective in expanding tissues as some studies show(with collagenase injections). Enzymes has a potential to pass through the skin barrier with an appropriate transdermal agent like DMSO, although it yet to be seen DMSO/collagenase benefits in PE. But you are correct with regards to relaxin, it is complex peptide and cannot be passed through the skin, but when injected directly has a very strong remodeling properties on a tissue in subject. What concerns my opinion on hydrocortisone, it is catabolic agent, meaning it signaling tissue break down, downside of it that it breaks down muscle tissue(unwanted effect for an erection quality), not to mention systemic circulation and skeletal muscle atrophy (I don’t believe turning into girlie and weak men is what this forum is about).